This invention is directed to a telecommunication system in which a plurality of channels (calls) are transported using an asynchronous node as at least part of the system. More specifically, this invention addresses the monitoring and controlling of the network in the presence of packet collisions which result in delays arising from the need to store the colliding packets in queues.
A conventional telecommunication system may utilize a switch such as an AT&T 5ESS.RTM. switch consisting of an administrative module, a communications module, and switching modules which support a plurality of telephone subscribers. The switch modules and the communications module each provide synchronous communication channels in which an originating and a terminating subscriber are assigned respective channels or time slots by which information is transmitted between the subscribers. Since the communications module provides a synchronous communication link with the switch modules, delays or queuing problems are not encountered because each communication path is assigned a time slot which is maintained for the duration of the call.
Asynchronous data communication systems such as those using packets to carry information provide an alternative to the synchronous communication systems typically utilized for voice communications. Since an asynchronous communication system will not have a unique time slot for each packet, it is possible that a plurality of packets destined for the same node may result in the need to buffer or store packets for delivery to the node. The depth or number of packets which must be stored in a queue provides an increased timing delay for packets traversing such a system. Such timing delays may become critical in certain applications such as when voice communications are also carried by other equipment in the system having time delay limits such as synchronous communications equipment. Thus, there exists a need in such a network to monitor and limit time delays due to collisions and queuing delays to maintain the quality of communications.